package Elegant.utils.bitmap
{
	
	import flash.display.BitmapData;
	import flash.display.BlendMode;
	import flash.display.DisplayObject;
	import flash.display.Sprite;
	
	import flash.geom.ColorTransform;
	import flash.geom.Matrix;
	import flash.geom.Point;
	import flash.geom.Rectangle;
	
	public class HitTest
	{
		
		
		public static function complexHitTestObject(target1:DisplayObject, target2:DisplayObject, accurracy:Number=1):Boolean
		{
			return complexIntersectionRectangle(target1, target2, accurracy).width != 0;
		}
		
		public static function intersectionRectangle(target1:DisplayObject, target2:DisplayObject):Rectangle
		{
			// If either of the items don't have a reference to stage, then they are not in a display list
			// or if a simple hitTestObject is false, they cannot be intersecting.
			if(!target1.root || !target2.root || !target1.hitTestObject(target2))
				return new Rectangle();
			
			// Get the bounds of each DisplayObject.
			var bounds1:Rectangle = target1.getBounds(target1.root);
			var bounds2:Rectangle = target2.getBounds(target2.root);
			
			// Determine test area boundaries.
			var intersection:Rectangle = new Rectangle();
			intersection.x = Math.max(bounds1.x, bounds2.x);
			intersection.y = Math.max(bounds1.y, bounds2.y);
			intersection.width = Math.min((bounds1.x + bounds1.width) - intersection.x, (bounds2.x + bounds2.width) - intersection.x);
			intersection.height = Math.min((bounds1.y + bounds1.height) - intersection.y, (bounds2.y + bounds2.height) - intersection.y);
			
			return intersection;
		}
		
		public static function complexIntersectionRectangle(target1:DisplayObject, target2:DisplayObject, accurracy:Number=1):Rectangle
		{
			if(accurracy <= 0)
				throw new Error("ArgumentError: Error #5001: Invalid value for accurracy", 5001);
			
			// If a simple hitTestObject is false, they cannot be intersecting.
			if(!target1.hitTestObject(target2))
				return new Rectangle();
			
			var hitRectangle:Rectangle = intersectionRectangle(target1, target2);
			// If their boundaries are no interesecting, they cannot be intersecting.
			if(hitRectangle.width * accurracy < 1 || hitRectangle.height * accurracy < 1)
				return new Rectangle();
			
			var bitmapData:BitmapData = new BitmapData(hitRectangle.width * accurracy, hitRectangle.height * accurracy, false, 0x000000);
			
			
			// Draw the first target.
			bitmapData.draw(target1, HitTest.getDrawMatrix(target1, hitRectangle, accurracy), new ColorTransform(1, 1, 1, 1, 255, -255, -255, 255));
			// Overlay the second target.
			bitmapData.draw(target2, HitTest.getDrawMatrix(target2, hitRectangle, accurracy), new ColorTransform(1, 1, 1, 1, 255, 255, 255, 255), BlendMode.DIFFERENCE);
			
			// Find the intersection.
			var intersection:Rectangle = bitmapData.getColorBoundsRect(0xFFFFFFFF, 0xFF00FFFF);
			
			bitmapData.dispose();
			
			// Alter width and positions to compensate for accurracy
			if(accurracy != 1)
			{
				intersection.x /= accurracy;
				intersection.y /= accurracy;
				intersection.width /= accurracy;
				intersection.height /= accurracy;
			}
			
			intersection.x += hitRectangle.x;
			intersection.y += hitRectangle.y;
			
			return intersection;
		}
		
		
		protected static function getDrawMatrix(target:DisplayObject, hitRectangle:Rectangle, accurracy:Number):Matrix
		{
			var localToGlobal:Point;
			var matrix:Matrix;
			
			var rootConcatenatedMatrix:Matrix = target.root.transform.concatenatedMatrix;
			
			localToGlobal = target.localToGlobal(new Point());
			matrix = target.transform.concatenatedMatrix;
			matrix.tx = localToGlobal.x - hitRectangle.x;
			matrix.ty = localToGlobal.y - hitRectangle.y;
			
			matrix.a = matrix.a / rootConcatenatedMatrix.a;
			matrix.d = matrix.d / rootConcatenatedMatrix.d;
			if(accurracy != 1)
				matrix.scale(accurracy, accurracy);
			
			
			return matrix;
		}
	
	
	}


}